My father has a pacemaker. I've been told that Rife machines shouldn't be used in these cases. Any advice?

This is true of Rife machines that only use electrodes, and the problem arises because the electrical energy entering the body can interfere with the pacemaker’s electronics. Consequently, it will also arise if you use Spooky- in Contact Mode - so please don't.Remote Mode doesn’t transmit electricity, however - so it’s quite safe for everyone.